1. Field of the Invention
The present invention relates to a continuous-filling packaging system in which containers (e.g., bags) are subjected to various packaging operations such as filling of the containers with the contents and sealing of the opening parts, etc., while the containers are continuously conveyed at a high speed; and more particularly to an intermittent container discharge device which is used in such a packaging system so as to convert the movement of full containers (filled containers) that are continuously conveyed in a single row into an intermittent movement in a plurality of rows.
2. Prior Art
Conventional retainer type filling packaging systems, in which bags are accommodated in retainers, and packaging operations are performed on the bags inside the retainers while the retainers are being conveyed, are described in, for example, Japanese Patent Application Laid-Open (Kokai) Nos. S58-73501 and S58-82801.
These systems are designed in the following manner:
A plurality of retainers which have been conveyed by a single-row conveyor are temporarily stopped and arranged, and a group of retainers which takes this plurality of containers as a unit is intermittently caused to advance, so that this group of retainers is fed onto an intermittently driven multi-row conveyor. Empty bags are simultaneously inserted into this group of retainers on the multi-row conveyor; then, after the mouths of the respective bags have been opened, the retainers of the above-described group are simultaneously pushed out from the multi-row conveyor onto a single-row conveyor. The retainers that have been thus pushed out onto this single-row conveyor are continuously conveyed and are continuously subjected to various packaging operations by a rotary type filling device, sealing device and cooling sealing device. The retainers are then again pushed onto an intermittently driven multi-row conveyor from the single-row conveyor as a group of retainers in which the above-described multiple number of containers are taken as a unit. The retainers are subjected to a cooling operation on this multi-layer conveyor. Furthermore, the discharge operation which extracts the full bags (filled bags) from the retainers is performed in the vicinity of the terminal end of the multi-layer conveyor, and the empty retainer group is pushed back out onto the single-row conveyor.
In such a retainer type filling packaging system, the efficiency of bag supply and discharge is increased by simultaneously supplying empty bags into a plurality of retainers or simultaneously extracting full bags from a plurality of retainers, so that continuity of processing with other devices that can be continuously operated at a high speed (filling devices, sealing devices, etc.) is maintained, thus improving productivity.
However, there are limits to the possible speed increase of the above-described intermittent operation itself, in which continuously conveyed retainers are temporarily stopped, and are then pushed by a pusher after a plurality of retainers have been gathered together. Accordingly, if an even greater improvement in bag supply and discharge efficiency is to be made, the number of containers handled as a group must be increased. If the number of retainers handled as a group is increased and the multi-row conveyor is widened, other problems occur. Installation of the insertion means used to insert bags into the retainers on the multi-row conveyor and the extraction means used to extract bags from the retainers becomes difficult. In particular, the replenishment of bags and maintenance in the portion of the insertion means positioned near the center of the multi-layer conveyor become difficult.
Furthermore, when the intermittent operation in which continuously conveyed retainers are temporarily stopped and a plurality of retainers are pushed out together by a pusher is performed, a large noise is constantly generated as a result of the retainers colliding with each other or with the pusher. This noise increases as the speed of the intermittent operation is increased.
In the retainer type filling packaging system, a much higher operating speed is possible for the rotary type filling device and sealing device. However, the intermittent operation in the supply of bags to the retainers and the discharge of the bags from the retainers forms a bottleneck, so that the improvement in the production efficiency of the retainer type filling packaging system as a whole is limited as described above. Though it is not impossible to perform the discharge of the bags from the retainers in a continuous manner on a single-row conveyor, if a high-speed operation is performed, a large quantity of bags exceeding the processing capacity per row will be conveyed in one row on the discharge conveyor. As a result, problems occur in subsequent processes such as packing the bags into boxes, etc.
In another type of filling packaging system that can be continuously operated at a high speed, such as the spout-equipped bag filling packaging system, a continuous packaging processing at a high speed by means of rotary type devices can be performed for the insertion of the spouts into the bags, the sealing of the mouths of the bags, the filling of the bags with a liquid following the attachment of the spouts, and the capping of the bags, etc. However, problems that are more or less similar to those seen in a retainer type filling packaging system occur. The intermittent operation involved in the supply of the bags similarly forms a bottleneck, and the improvement in the production efficiency of the spout-equipped bag filling packaging system as a whole is limited.
The present invention is made in light of the above-described conventional problems.
One object of the present invention is to improve productivity in a continuous-filling packaging system for containers by increasing the speed of the full container discharge operation and allowing a high-speed operation of the system as a whole.
Furthermore, another object of the present invention, especially in a retainer type system, is to obtain a discharge device which continuously extracts full containers from retainers continuously conveyed in a single row without stopping the retainers and discharges these full containers to the outside of the system after converting only the movement of the full containers into an intermittent movement in a plurality of rows.
Still another object of the present invention is to prevent the number of bags (or containers) conveyed per row from exceeding the treatment capacity of the subsequent process by discharging the continuously conveyed full containers after converting the single row of containers into a plurality of rows of containers.
The present invention is for an intermittent container discharge device which is used in a continuous-filling packaging system, and it converts the movement of full containers that are continuously fed in a single row into an intermittent movement in a plurality of rows and discharges the full containers out of the packaging system.
More specifically, the intermittent container discharge device is equipped with a container holding member conveying device in which numerous container holding members disposed at equal intervals are moved in one direction along a ring-form track (or a race-track shape path) which has a pair of parallel sections, and in which, during this movement, the container holding members are moved continuously at a constant speed on a first side of the parallel sections and are moved intermittently a certain distance (which is a distance equal to an integral multiple of an attachment spacing of the container holding members) on a second side of the parallel sections; and the intermittent container discharge device continuously receives full containers by the continuously moving container holding members on the first side of the parallel sections and discharges full containers in a plurality of rows from the stopped container holding members on the second side of the parallel sections.
In the above structure, a product-conveying device, which receives full bags (or full containers) discharged in a plurality of rows from the container holding members and conveys these full bags xe2x80x9cas isxe2x80x9d in a plurality of rows, may be installed on the second side of the parallel section of the ring-form track.
The above-described container holding member conveying device is equipped with, for instance, a rotational conveying mechanism and a reciprocating driving mechanism. The rotational conveying mechanism rotationally conveys numerous container holding members disposed at equal intervals in one direction along the ring-form track which has a pair of parallel sections, and the reciprocating driving mechanism causes the rotational conveying mechanism as a whole to perform a reciprocating movement through a specified distance along the parallel sections. The rotational conveying mechanism and reciprocating driving mechanism are equipped with respectively independent driving sources. The container holding members have a movement speed resulting from the synthesis of the rotational conveyance and the reciprocating movement.
When the above-described continuous-filling packaging system is a retainer type system, it is preferable to install a retainer conveying device which continuously conveys numerous retainers accommodating full containers at the same intervals as the intervals of the container holding members and at the same speed as the movement speed of the container holding members along the first side of the parallel sections, so that full containers accommodated inside the retainers are received by the container holding members. In this case, the container holding members are raised and lowered while being moved along the ring-form track, so that the container holding members are lowered on the first side of the parallel sections to grip the full bags accommodated inside the retainers and then raised to extract the full bags from the retainers.
Furthermore, a loop type transfer device can be installed, on the first side of the parallel sections, as a part of the above-described intermittent container discharge device. The loop type transfer device includes numerous transfer means that are disposed at equal intervals and moved continuously at a constant speed along a fixed-position ring-form track which has a pair of parallel sections. This loop type transfer device continuously receives full containers through the continuously moving transfer means on a first side of the parallel sections of the fixed-position ring-form track, and continuously supplies these full containers to the continuously moving container holding members on a second side of the parallel section. In other words, in this case, the above-described container holding member conveying device continuously receives full containers via the loop type transfer device and intermittently discharges the full containers in a plurality of rows. Needless to say, the attachment spacing and movement speed of the transfer means are set so as to agree with those of the container holding members.
In cases where the continuous-filling packaging system equipped with this intermittent container discharge device is a retainer type system, it is preferable to install a retainer conveying device. This retainer conveying device conveys numerous retainers accommodating full containers at the same intervals as the intervals of the container holding members and at the same speed as the movement speed of the container holding members along the first side of the parallel sections of the fixed-position ring-form track of the loop type transfer device, so that full containers accommodated in the continuously moving retainers are received by the transfer means. In this case, the above-described transfer means are caused to be raised and lowered at a specified timing while being moved along the fixed-position ring-form track, so that the transfer means is lowered on the first side of the parallel sections to grip the full bags accommodated inside the retainers and then is raised to extract the full bags from the retainers.
Furthermore, a rotary type transfer device which has numerous transfer means disposed at equal intervals may be installed on the first side of the above-described parallel sections as a part of the intermittent container discharge device. This rotary type transfer device continuously receives full containers from the rotor of a device which is of the preceding process through the continuously rotating transfer means and then continuously supplies these full containers to the container holding members. In other words, in this case, the container holding member conveying device continuously receives full containers via the rotary type transfer device and intermittently discharges the full containers in a plurality of rows. Needless to say, the attachment spacing and rotational movement speed of the transfer means are set to agree with those of the container holding members.